Carotenoids are referred to herein as a group of unsaturated hydrocarbons containing isoprene units or their derivatives substituted by various functional groups in lipid addition compounds of the same (i.e., prenyl-lipids). Carotenoids include, but are not limited to lycopene, beta-carotene, alpha-carotene, xanthophyll, etc.
A healthy diet involves the consumption of appropriate amounts of high quality fruits and vegetables, of which carotenoids are essential components. For example, carotenoids, such as lycopene and beta-carotene, are highly effective antioxidants and may also have provitamin functions. In fact, diets rich in these carotenoids are recognized as reducing the risks of various diseases, including prostate cancer and cardiovascular disease.
In previously developed carotenoid extraction methods, lipophilic solvents are used, including both toxic and non-toxic solvents. Toxic solvents (such as hexane and chlorinated hydrocarbons) can leave trace residues that migrate and accumulate in target cells and tissues. Non-toxic solvents (such as ethanol, rectified alcohol, and isopropyl alcohol), although non-toxic, are also disadvantageous in food processing. These solvents not only create flammability and explosion safety hazards in the food processing plant in which they are used, but also require disclosure of solvent content in the final product.
In view of the advantageous effects of the consumption of carotenoids and the drawbacks of the previously developed extraction methods, there exists a need for improved methods to extract carotenoids from plant material for consumption.